Training in whatever they’re actually going to do/practice.
They can be a neurologist, a cardiologist, a urologist, a psychiatrist any day of the week with zero education/training in that outside some cursory or happenstance educational moments… then two weeks later they can switch to something completely different.
No one cares if a doctor has a “rigorous” medical school experience and surely no one trusts a doctor even after that type of experience if it diesnt come with a formal residency